Nuclear magnetic properties generally refer to the local magnetic and electric fields which atoms exert upon each other. The local magnetic and electric fields are a sensitive probe of the local environment and the chemical structure of the substance of which the atoms compose. However, these fields are generally too weak to be probed directly. An attempt to probe these fields usually results in a severe loss or distortion of information. The fields produced by the apparatus used to probe the local magnetic and electric fields, or even the earth's own magnetic field, may "mask" the local fields which are desired to be measured.
The techniques of nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) have been developed and provide a valuable tool for determining molecular structure characteristics. These molecular structural characteristics are useful in determining factors which influence chemical changes.
The typical prior art nuclear magnetic resonance detection system operates by first placing the sample to be measured within a relatively high magnetic field. The magnetic field causes the magnetic dipoles at the atomic level to align their axis within this field. The axis is the nuclear spin axis of each nuclei. After the sample has been exposed to the magnetic field for a sufficient time, the sample reaches magnetic equilibrium. Once equilibrium has been obtained, the local magnetic fields may be measured. The measurement usually consists of a radio frequency detector which is scanned across the sample. The frequency emitted by each magnetic dipole is unique for each atomic element present in the molecular structure. Thus, the chemical structure of the sample is determined by the spectrum of radio frequencies detected by the RF detector.
One particularly useful application for NMR detection is to study the effects of catalyst materials. It is highly desirable to be able to predict when a material will exhibit catalytic behavior, and furthermore, to predict the most favorable conditions to optimize the results of the catalytic behavior. However, the use of prior known NMR and NQR detection techniques for analyzing the molecular structures of solid materials has presented several limitations and disadvantages. For example, prior NMR procedures for the studies of solids usually have required the use of a single crystal or oriented sample. However, many solids which are desired to be measured are not single crystal or oriented samples. For example, it is desirable to determine the molecular structure of powdered samples or amorphous samples. Furthermore, known prior art methods and apparatus for obtaining NMR spectra usually have a disadvantage and limitation in crystallography and molecular structure determination in polycrystalline or disordered materials.